I think you're really asking why hockey hasn't produced a conversation around whether its current top players are actually the GOATs, or whatever. That's a media question, with the very obvious conclusion that its hype sphere is contained.
Most of the MLB players with the highest batting averages are dead. Football is a monstrous mess and it's hard to separate a great player from a great team (or scheme). There are numerous NBA players who have won more championships than Lebron, Kobe, or MJ....and while current players might have more impressive offensive numbers, basketball has shifted towards increased offense rather than away from it, as hockey has. Hell, call me when the 1.5-goal line has been created.
Crosby might be the best hockey player to ever live. He might actually be better than Gretzky, but the way the game is played today won't tell you that. Likewise, Mike Trout might be better than Ty Cobb, but short of reanimating one to play today or sending the other back in time, you'll never know.
It's all a construct.
EDIT: Now, an addendum to that is this: Gretzky, as mentioned above, is a massive barrier. He really might be the greatest team-sport athlete to ever live, and if you dropped him in the game today he'd put up terrific numbers still. But he wouldn't be scoring 200 points, we all know that.